But when thousands died in Christian-Muslim clashes in the 1980s, and thousands more in riots in Kano in 1991, no prolonged fighting followed.
In 2003, these fears and conspiracy theories led to the suspension of vaccination campaigns in Kano, leading to a high number of children contracting the disease.
But during a court hearing in Kano, prosecutors brought lesser charges that included conspiracy, inciting a disturbance and obstruction of a public servant, AP news agency reports.
The lawsuit, filed in a US District Court on Wednesday, seeks unspecified damages on behalf of 30 children who took part in trials in Kano, in northern Nigeria.
The emir's convoy was attacked by unknown gunmen as he was returning from Koranic graduation ceremony in Kano city, Kano state governor Musa Rabiu Kwankwaso told AFP news agency.
Suspicions about vaccination programmes were fuelled in part by the Pfizer scandal in 1996 when the US drugs firm used an experimental drug during a meningitis outbreak in Kano.
The BBC's Abdullahi Kaura Abubakar in Kano says the Sunday evening attack on a police station in the Naibawa district, on the outskirts of Kano, happened just before the start of the dusk-to-dawn curfew.
In October 2003, the government of Kano State in Nigeria stopped an ongoing polio vaccination program and did not allow it to resume until August 2004.
CENTERFORSECURITYPOLICY: An African Vortex: Islamism in Sub-Saharan Africa
He was shot dead on 20 January the city of Kano, in northern Nigeria.
The group was blamed for an attack in April in the city of Kano.
Created by Kano Jigoro in the late 19th century, judo is derived from the techniques of jujitsu, an older art of self-defense that seeks advantage by throwing an opponent off balance.
Nigerian troops say they have killed 14 suspected members of the Islamist rebel group Boko Haram, in a raid on a building in the northern city of Kano.
Isa, a cameraman for the Nigerian Television Authority (NTA), was killed in October 2011, and Akogwu, a news reporter with Channels Television, was shot and killed, having covered the Kano bomb blast in January.
The military statement said Mr Zangina was leader of Boko Haram in the "North Central part of Nigeria and co-ordinator of most of the suicide attacks and bombings in Abuja, Kaduna, Kano, Jos and Potiskum".
On his private jet, the Nigerian billionaire Aliko Dangote - whose business empire includes production of cement, flour and sugar - explained why he is involved in an initiative to double immunisation efforts in his home state, Kano.
These attacks followed an attempt on the life of the second most important Muslim leader in Nigeria, the Emir of Kano, whose convoy came under fire on Sunday.
Believing that the league is unattractive, amateurishly run and constantly haemorrhages its best players, Nigerian football fans - those backing Kano Pillars aside - have not come out in numbers to attend games.
应用推荐